You cannot remove the valance without removing the shade first.
I am through restringing these things. I am ordering the MCD blinds.
I installed one of the MCD blinds last year. They are no box of chocolates to install either.
But I will take down the valance to install the clips needed for the MCD blinds. Then install the valance, then the MCD blind. Tip on MCD, do not remove the tape and cardboard filler until AFTER you hook it in to the brackets. Ask me how I know.